dc barrel jack & breadboard, how to?

[joedamato]

Hello,

I need to add an external power supply for a dc motor.

I have an adapter and a breadboard and an arduino uno.

So, it seems the jack barrel is what I need to add some wired power. Now these barrels have 3 legs. Which is which to connect the power and the ground to?
https://www.adafruit.com/products/373. Maybe I don't clearly understand the datasheet.

Could you help me on this?

Thanks

[joedamato]

from here https://learn.adafruit.com/assets/11910,

maybe the bottom pin is the + and the two others are both the -.

Confirmation?

[Franklin97355]

I have an adapter and a breadboard and an arduino uno.

You need to find how your adapter is wired and supplies power and then connect the jack the same way. The datasheet for our jack is here.

[ekaz]

Same, I purchased a 5v power supply and the dc barrel jack. The datasheet schematic is not clear on which is positive and which is negative. Help?

[Franklin97355]

There is no positive or negative, that will depend on what the polarity is on your power supply and should be marked on it. Usually it is center positive but not always make sure you check before applying power.

[ekaz]

Thank you for the fast response, unfortunately, there is no datasheet on the power supply itself. So I can't trace its polarity to the dc barrel jack? https://www.adafruit.com/products/276

[Franklin97355]

If you look at the label (second picture) you will see it is center positive.

[ekaz]

Great, so does that mean that the pin 3 on the dc barrel jack is feeding connected to the center? In other words, does pin 3 of the barrel indicate +ve while the either 1 or 2 is -ve, and if so which one. Am sorry for the questions but I am not familiar with jack schematics?

[Franklin97355]

1 is + and 2 is GND

[ekaz]

Thank you so much for your patience and guidance.